Dynamic model of ozone contacting process with oxygen mass transfer in bubble columns

Abstract

The dynamic process of the dissolution of ozone in a countercurrent bubble column is studied for model establishment. Bubble columns have been used widely for ozone contacting in the plant and laboratory. Ozone is produced by oxygen-enriched gas through an ozone generator, and introduced into the bottom of the column equipped with the gas diffuser. The ozone contacting system proceeds for a temporary and unsteady period before reaching steady state. The available ozone dissolution models employed for the description of the dissolved ozone profiles were commonly developed for the steady state. Moreover, oxygen mass transfer is usually neglected in the preceding ozone dissolution models. However, this information is desirable for proper operation of ozone dissolution in a bubble column. Thus, the objective of this study is to model and investigate the dynamic ozone dissolution process in a bubble column with the oxygen mass transfer. The dynamic axial dispersion model proposed is employed to predict the variations of ozone and oxygen concentrations along the column, and the amount of off-gas. The validity of the model is demonstrated by comparing the predicted results with the experimental data. The dynamic model of ozone dissolution is useful and referable for proper prediction of the variables of the ozone contacting system in a bubble column.